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[gcc.git] / gcc / tree-vectorizer.c

/* Vectorizer
   Copyright (C) 2003-2017 Free Software Foundation, Inc.
   Contributed by Dorit Naishlos <dorit@il.ibm.com>

This file is part of GCC.

GCC is free software; you can redistribute it and/or modify it under
the terms of the GNU General Public License as published by the Free
Software Foundation; either version 3, or (at your option) any later
version.

GCC is distributed in the hope that it will be useful, but WITHOUT ANY
WARRANTY; without even the implied warranty of MERCHANTABILITY or
FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
for more details.

You should have received a copy of the GNU General Public License
along with GCC; see the file COPYING3.  If not see
<http://www.gnu.org/licenses/>.  */

/* Loop and basic block vectorizer.

  This file contains drivers for the three vectorizers:
  (1) loop vectorizer (inter-iteration parallelism),
  (2) loop-aware SLP (intra-iteration parallelism) (invoked by the loop
      vectorizer)
  (3) BB vectorizer (out-of-loops), aka SLP

  The rest of the vectorizer's code is organized as follows:
  - tree-vect-loop.c - loop specific parts such as reductions, etc. These are
    used by drivers (1) and (2).
  - tree-vect-loop-manip.c - vectorizer's loop control-flow utilities, used by
    drivers (1) and (2).
  - tree-vect-slp.c - BB vectorization specific analysis and transformation,
    used by drivers (2) and (3).
  - tree-vect-stmts.c - statements analysis and transformation (used by all).
  - tree-vect-data-refs.c - vectorizer specific data-refs analysis and
    manipulations (used by all).
  - tree-vect-patterns.c - vectorizable code patterns detector (used by all)

  Here's a poor attempt at illustrating that:

     tree-vectorizer.c:
     loop_vect()  loop_aware_slp()  slp_vect()
          |        /           \          /
          |       /             \        /
          tree-vect-loop.c  tree-vect-slp.c
                | \      \  /      /   |
                |  \      \/      /    |
                |   \     /\     /     |
                |    \   /  \   /      |
         tree-vect-stmts.c  tree-vect-data-refs.c
                       \      /
                    tree-vect-patterns.c
*/

#include "config.h"
#include "system.h"
#include "coretypes.h"
#include "backend.h"
#include "tree.h"
#include "gimple.h"
#include "predict.h"
#include "tree-pass.h"
#include "ssa.h"
#include "cgraph.h"
#include "fold-const.h"
#include "stor-layout.h"
#include "gimple-iterator.h"
#include "gimple-walk.h"
#include "tree-ssa-loop-manip.h"
#include "tree-ssa-loop-niter.h"
#include "tree-cfg.h"
#include "cfgloop.h"
#include "tree-vectorizer.h"
#include "tree-ssa-propagate.h"
#include "dbgcnt.h"
#include "tree-scalar-evolution.h"


/* Loop or bb location.  */
source_location vect_location;

/* Vector mapping GIMPLE stmt to stmt_vec_info. */
vec<stmt_vec_info> stmt_vec_info_vec;
\f
/* For mapping simduid to vectorization factor.  */

struct simduid_to_vf : free_ptr_hash<simduid_to_vf>
{
  unsigned int simduid;
  int vf;

  /* hash_table support.  */
  static inline hashval_t hash (const simduid_to_vf *);
  static inline int equal (const simduid_to_vf *, const simduid_to_vf *);
};

inline hashval_t
simduid_to_vf::hash (const simduid_to_vf *p)
{
  return p->simduid;
}

inline int
simduid_to_vf::equal (const simduid_to_vf *p1, const simduid_to_vf *p2)
{
  return p1->simduid == p2->simduid;
}

/* This hash maps the OMP simd array to the corresponding simduid used
   to index into it.  Like thus,

        _7 = GOMP_SIMD_LANE (simduid.0)
        ...
        ...
        D.1737[_7] = stuff;


   This hash maps from the OMP simd array (D.1737[]) to DECL_UID of
   simduid.0.  */

struct simd_array_to_simduid : free_ptr_hash<simd_array_to_simduid>
{
  tree decl;
  unsigned int simduid;

  /* hash_table support.  */
  static inline hashval_t hash (const simd_array_to_simduid *);
  static inline int equal (const simd_array_to_simduid *,
                           const simd_array_to_simduid *);
};

inline hashval_t
simd_array_to_simduid::hash (const simd_array_to_simduid *p)
{
  return DECL_UID (p->decl);
}

inline int
simd_array_to_simduid::equal (const simd_array_to_simduid *p1,
                              const simd_array_to_simduid *p2)
{
  return p1->decl == p2->decl;
}

/* Fold IFN_GOMP_SIMD_LANE, IFN_GOMP_SIMD_VF, IFN_GOMP_SIMD_LAST_LANE,
   into their corresponding constants and remove
   IFN_GOMP_SIMD_ORDERED_{START,END}.  */

static void
adjust_simduid_builtins (hash_table<simduid_to_vf> *htab)
{
  basic_block bb;

  FOR_EACH_BB_FN (bb, cfun)
    {
      gimple_stmt_iterator i;

      for (i = gsi_start_bb (bb); !gsi_end_p (i); )
        {
          unsigned int vf = 1;
          enum internal_fn ifn;
          gimple *stmt = gsi_stmt (i);
          tree t;
          if (!is_gimple_call (stmt)
              || !gimple_call_internal_p (stmt))
            {
              gsi_next (&i);
              continue;
            }
          ifn = gimple_call_internal_fn (stmt);
          switch (ifn)
            {
            case IFN_GOMP_SIMD_LANE:
            case IFN_GOMP_SIMD_VF:
            case IFN_GOMP_SIMD_LAST_LANE:
              break;
            case IFN_GOMP_SIMD_ORDERED_START:
            case IFN_GOMP_SIMD_ORDERED_END:
              if (integer_onep (gimple_call_arg (stmt, 0)))
                {
                  enum built_in_function bcode
                    = (ifn == IFN_GOMP_SIMD_ORDERED_START
                       ? BUILT_IN_GOMP_ORDERED_START
                       : BUILT_IN_GOMP_ORDERED_END);
                  gimple *g
                    = gimple_build_call (builtin_decl_explicit (bcode), 0);
                  tree vdef = gimple_vdef (stmt);
                  gimple_set_vdef (g, vdef);
                  SSA_NAME_DEF_STMT (vdef) = g;
                  gimple_set_vuse (g, gimple_vuse (stmt));
                  gsi_replace (&i, g, true);
                  continue;
                }
              gsi_remove (&i, true);
              unlink_stmt_vdef (stmt);
              continue;
            default:
              gsi_next (&i);
              continue;
            }
          tree arg = gimple_call_arg (stmt, 0);
          gcc_assert (arg != NULL_TREE);
          gcc_assert (TREE_CODE (arg) == SSA_NAME);
          simduid_to_vf *p = NULL, data;
          data.simduid = DECL_UID (SSA_NAME_VAR (arg));
          /* Need to nullify loop safelen field since it's value is not
             valid after transformation.  */
          if (bb->loop_father && bb->loop_father->safelen > 0)
            bb->loop_father->safelen = 0;
          if (htab)
            {
              p = htab->find (&data);
              if (p)
                vf = p->vf;
            }
          switch (ifn)
            {
            case IFN_GOMP_SIMD_VF:
              t = build_int_cst (unsigned_type_node, vf);
              break;
            case IFN_GOMP_SIMD_LANE:
              t = build_int_cst (unsigned_type_node, 0);
              break;
            case IFN_GOMP_SIMD_LAST_LANE:
              t = gimple_call_arg (stmt, 1);
              break;
            default:
              gcc_unreachable ();
            }
          update_call_from_tree (&i, t);
          gsi_next (&i);
        }
    }
}

/* Helper structure for note_simd_array_uses.  */

struct note_simd_array_uses_struct
{
  hash_table<simd_array_to_simduid> **htab;
  unsigned int simduid;
};

/* Callback for note_simd_array_uses, called through walk_gimple_op.  */

static tree
note_simd_array_uses_cb (tree *tp, int *walk_subtrees, void *data)
{
  struct walk_stmt_info *wi = (struct walk_stmt_info *) data;
  struct note_simd_array_uses_struct *ns
    = (struct note_simd_array_uses_struct *) wi->info;

  if (TYPE_P (*tp))
    *walk_subtrees = 0;
  else if (VAR_P (*tp)
           && lookup_attribute ("omp simd array", DECL_ATTRIBUTES (*tp))
           && DECL_CONTEXT (*tp) == current_function_decl)
    {
      simd_array_to_simduid data;
      if (!*ns->htab)
        *ns->htab = new hash_table<simd_array_to_simduid> (15);
      data.decl = *tp;
      data.simduid = ns->simduid;
      simd_array_to_simduid **slot = (*ns->htab)->find_slot (&data, INSERT);
      if (*slot == NULL)
        {
          simd_array_to_simduid *p = XNEW (simd_array_to_simduid);
          *p = data;
          *slot = p;
        }
      else if ((*slot)->simduid != ns->simduid)
        (*slot)->simduid = -1U;
      *walk_subtrees = 0;
    }
  return NULL_TREE;
}

/* Find "omp simd array" temporaries and map them to corresponding
   simduid.  */

static void
note_simd_array_uses (hash_table<simd_array_to_simduid> **htab)
{
  basic_block bb;
  gimple_stmt_iterator gsi;
  struct walk_stmt_info wi;
  struct note_simd_array_uses_struct ns;

  memset (&wi, 0, sizeof (wi));
  wi.info = &ns;
  ns.htab = htab;

  FOR_EACH_BB_FN (bb, cfun)
    for (gsi = gsi_start_bb (bb); !gsi_end_p (gsi); gsi_next (&gsi))
      {
        gimple *stmt = gsi_stmt (gsi);
        if (!is_gimple_call (stmt) || !gimple_call_internal_p (stmt))
          continue;
        switch (gimple_call_internal_fn (stmt))
          {
          case IFN_GOMP_SIMD_LANE:
          case IFN_GOMP_SIMD_VF:
          case IFN_GOMP_SIMD_LAST_LANE:
            break;
          default:
            continue;
          }
        tree lhs = gimple_call_lhs (stmt);
        if (lhs == NULL_TREE)
          continue;
        imm_use_iterator use_iter;
        gimple *use_stmt;
        ns.simduid = DECL_UID (SSA_NAME_VAR (gimple_call_arg (stmt, 0)));
        FOR_EACH_IMM_USE_STMT (use_stmt, use_iter, lhs)
          if (!is_gimple_debug (use_stmt))
            walk_gimple_op (use_stmt, note_simd_array_uses_cb, &wi);
      }
}

/* Shrink arrays with "omp simd array" attribute to the corresponding
   vectorization factor.  */

static void
shrink_simd_arrays
  (hash_table<simd_array_to_simduid> *simd_array_to_simduid_htab,
   hash_table<simduid_to_vf> *simduid_to_vf_htab)
{
  for (hash_table<simd_array_to_simduid>::iterator iter
         = simd_array_to_simduid_htab->begin ();
       iter != simd_array_to_simduid_htab->end (); ++iter)
    if ((*iter)->simduid != -1U)
      {
        tree decl = (*iter)->decl;
        int vf = 1;
        if (simduid_to_vf_htab)
          {
            simduid_to_vf *p = NULL, data;
            data.simduid = (*iter)->simduid;
            p = simduid_to_vf_htab->find (&data);
            if (p)
              vf = p->vf;
          }
        tree atype
          = build_array_type_nelts (TREE_TYPE (TREE_TYPE (decl)), vf);
        TREE_TYPE (decl) = atype;
        relayout_decl (decl);
      }

  delete simd_array_to_simduid_htab;
}
\f
/* A helper function to free data refs.  */

void
vect_destroy_datarefs (vec_info *vinfo)
{
  struct data_reference *dr;
  unsigned int i;

  FOR_EACH_VEC_ELT (vinfo->datarefs, i, dr)
    if (dr->aux)
      {
        free (dr->aux);
        dr->aux = NULL;
      }

  free_data_refs (vinfo->datarefs);
}

/* A helper function to free scev and LOOP niter information, as well as
   clear loop constraint LOOP_C_FINITE.  */

void
vect_free_loop_info_assumptions (struct loop *loop)
{
  scev_reset_htab ();
  /* We need to explicitly reset upper bound information since they are
     used even after free_numbers_of_iterations_estimates_loop.  */
  loop->any_upper_bound = false;
  loop->any_likely_upper_bound = false;
  free_numbers_of_iterations_estimates_loop (loop);
  loop_constraint_clear (loop, LOOP_C_FINITE);
}

/* Return whether STMT is inside the region we try to vectorize.  */

bool
vect_stmt_in_region_p (vec_info *vinfo, gimple *stmt)
{
  if (!gimple_bb (stmt))
    return false;

  if (loop_vec_info loop_vinfo = dyn_cast <loop_vec_info> (vinfo))
    {
      struct loop *loop = LOOP_VINFO_LOOP (loop_vinfo);
      if (!flow_bb_inside_loop_p (loop, gimple_bb (stmt)))
        return false;
    }
  else
    {
      bb_vec_info bb_vinfo = as_a <bb_vec_info> (vinfo);
      if (gimple_bb (stmt) != BB_VINFO_BB (bb_vinfo)
          || gimple_uid (stmt) == -1U
          || gimple_code (stmt) == GIMPLE_PHI)
        return false;
    }

  return true;
}


/* If LOOP has been versioned during ifcvt, return the internal call
   guarding it.  */

static gimple *
vect_loop_vectorized_call (struct loop *loop)
{
  basic_block bb = loop_preheader_edge (loop)->src;
  gimple *g;
  do
    {
      g = last_stmt (bb);
      if (g)
        break;
      if (!single_pred_p (bb))
        break;
      bb = single_pred (bb);
    }
  while (1);
  if (g && gimple_code (g) == GIMPLE_COND)
    {
      gimple_stmt_iterator gsi = gsi_for_stmt (g);
      gsi_prev (&gsi);
      if (!gsi_end_p (gsi))
        {
          g = gsi_stmt (gsi);
          if (gimple_call_internal_p (g, IFN_LOOP_VECTORIZED)
              && (tree_to_shwi (gimple_call_arg (g, 0)) == loop->num
                  || tree_to_shwi (gimple_call_arg (g, 1)) == loop->num))
            return g;
        }
    }
  return NULL;
}

/* Fold LOOP_VECTORIZED internal call G to VALUE and
   update any immediate uses of it's LHS.  */

static void
fold_loop_vectorized_call (gimple *g, tree value)
{
  tree lhs = gimple_call_lhs (g);
  use_operand_p use_p;
  imm_use_iterator iter;
  gimple *use_stmt;
  gimple_stmt_iterator gsi = gsi_for_stmt (g);

  update_call_from_tree (&gsi, value);
  FOR_EACH_IMM_USE_STMT (use_stmt, iter, lhs)
    {
      FOR_EACH_IMM_USE_ON_STMT (use_p, iter)
        SET_USE (use_p, value);
      update_stmt (use_stmt);
    }
}
/* Set the uids of all the statements in basic blocks inside loop
   represented by LOOP_VINFO. LOOP_VECTORIZED_CALL is the internal
   call guarding the loop which has been if converted.  */
static void
set_uid_loop_bbs (loop_vec_info loop_vinfo, gimple *loop_vectorized_call)
{
  tree arg = gimple_call_arg (loop_vectorized_call, 1);
  basic_block *bbs;
  unsigned int i;
  struct loop *scalar_loop = get_loop (cfun, tree_to_shwi (arg));

  LOOP_VINFO_SCALAR_LOOP (loop_vinfo) = scalar_loop;
  gcc_checking_assert (vect_loop_vectorized_call
                       (LOOP_VINFO_SCALAR_LOOP (loop_vinfo))
                       == loop_vectorized_call);
  bbs = get_loop_body (scalar_loop);
  for (i = 0; i < scalar_loop->num_nodes; i++)
    {
      basic_block bb = bbs[i];
      gimple_stmt_iterator gsi;
      for (gsi = gsi_start_phis (bb); !gsi_end_p (gsi); gsi_next (&gsi))
        {
          gimple *phi = gsi_stmt (gsi);
          gimple_set_uid (phi, 0);
        }
      for (gsi = gsi_start_bb (bb); !gsi_end_p (gsi); gsi_next (&gsi))
        {
          gimple *stmt = gsi_stmt (gsi);
          gimple_set_uid (stmt, 0);
        }
    }
  free (bbs);
}

/* Function vectorize_loops.

   Entry point to loop vectorization phase.  */

unsigned
vectorize_loops (void)
{
  unsigned int i;
  unsigned int num_vectorized_loops = 0;
  unsigned int vect_loops_num;
  struct loop *loop;
  hash_table<simduid_to_vf> *simduid_to_vf_htab = NULL;
  hash_table<simd_array_to_simduid> *simd_array_to_simduid_htab = NULL;
  bool any_ifcvt_loops = false;
  unsigned ret = 0;
  struct loop *new_loop;

  vect_loops_num = number_of_loops (cfun);

  /* Bail out if there are no loops.  */
  if (vect_loops_num <= 1)
    return 0;

  if (cfun->has_simduid_loops)
    note_simd_array_uses (&simd_array_to_simduid_htab);

  init_stmt_vec_info_vec ();

  /*  ----------- Analyze loops. -----------  */

  /* If some loop was duplicated, it gets bigger number
     than all previously defined loops.  This fact allows us to run
     only over initial loops skipping newly generated ones.  */
  FOR_EACH_LOOP (loop, 0)
    if (loop->dont_vectorize)
      any_ifcvt_loops = true;
    else if ((flag_tree_loop_vectorize
              && optimize_loop_nest_for_speed_p (loop))
             || loop->force_vectorize)
      {
        loop_vec_info loop_vinfo, orig_loop_vinfo = NULL;
        gimple *loop_vectorized_call = vect_loop_vectorized_call (loop);
vectorize_epilogue:
        vect_location = find_loop_location (loop);
        if (LOCATION_LOCUS (vect_location) != UNKNOWN_LOCATION
            && dump_enabled_p ())
          dump_printf (MSG_NOTE, "\nAnalyzing loop at %s:%d\n",
                       LOCATION_FILE (vect_location),
                       LOCATION_LINE (vect_location));

        loop_vinfo = vect_analyze_loop (loop, orig_loop_vinfo);
        loop->aux = loop_vinfo;

        if (!loop_vinfo || !LOOP_VINFO_VECTORIZABLE_P (loop_vinfo))
          {
            /* Free existing information if loop is analyzed with some
               assumptions.  */
            if (loop_constraint_set_p (loop, LOOP_C_FINITE))
              vect_free_loop_info_assumptions (loop);

            /* If we applied if-conversion then try to vectorize the
               BB of innermost loops.
               ???  Ideally BB vectorization would learn to vectorize
               control flow by applying if-conversion on-the-fly, the
               following retains the if-converted loop body even when
               only non-if-converted parts took part in BB vectorization.  */
            if (flag_tree_slp_vectorize != 0
                && loop_vectorized_call
                && ! loop->inner)
              {
                basic_block bb = loop->header;
                bool has_mask_load_store = false;
                for (gimple_stmt_iterator gsi = gsi_start_bb (bb);
                     !gsi_end_p (gsi); gsi_next (&gsi))
                  {
                    gimple *stmt = gsi_stmt (gsi);
                    if (is_gimple_call (stmt)
                        && gimple_call_internal_p (stmt)
                        && (gimple_call_internal_fn (stmt) == IFN_MASK_LOAD
                            || gimple_call_internal_fn (stmt) == IFN_MASK_STORE))
                      {
                        has_mask_load_store = true;
                        break;
                      }
                    gimple_set_uid (stmt, -1);
                    gimple_set_visited (stmt, false);
                  }
                if (! has_mask_load_store && vect_slp_bb (bb))
                  {
                    dump_printf_loc (MSG_OPTIMIZED_LOCATIONS, vect_location,
                                     "basic block vectorized\n");
                    fold_loop_vectorized_call (loop_vectorized_call,
                                               boolean_true_node);
                    ret |= TODO_cleanup_cfg;
                  }
              }
            continue;
          }

        if (!dbg_cnt (vect_loop))
          {
            /* We may miss some if-converted loops due to
               debug counter.  Set any_ifcvt_loops to visit
               them at finalization.  */
            any_ifcvt_loops = true;
            /* Free existing information if loop is analyzed with some
               assumptions.  */
            if (loop_constraint_set_p (loop, LOOP_C_FINITE))
              vect_free_loop_info_assumptions (loop);

            break;
          }

        if (loop_vectorized_call)
          set_uid_loop_bbs (loop_vinfo, loop_vectorized_call);
        if (LOCATION_LOCUS (vect_location) != UNKNOWN_LOCATION
            && dump_enabled_p ())
          dump_printf_loc (MSG_OPTIMIZED_LOCATIONS, vect_location,
                           "loop vectorized\n");
        new_loop = vect_transform_loop (loop_vinfo);
        num_vectorized_loops++;
        /* Now that the loop has been vectorized, allow it to be unrolled
           etc.  */
        loop->force_vectorize = false;

        if (loop->simduid)
          {
            simduid_to_vf *simduid_to_vf_data = XNEW (simduid_to_vf);
            if (!simduid_to_vf_htab)
              simduid_to_vf_htab = new hash_table<simduid_to_vf> (15);
            simduid_to_vf_data->simduid = DECL_UID (loop->simduid);
            simduid_to_vf_data->vf = loop_vinfo->vectorization_factor;
            *simduid_to_vf_htab->find_slot (simduid_to_vf_data, INSERT)
              = simduid_to_vf_data;
          }

        if (loop_vectorized_call)
          {
            fold_loop_vectorized_call (loop_vectorized_call, boolean_true_node);
            ret |= TODO_cleanup_cfg;
          }

        if (new_loop)
          {
            /* Epilogue of vectorized loop must be vectorized too.  */
            vect_loops_num = number_of_loops (cfun);
            loop = new_loop;
            orig_loop_vinfo = loop_vinfo;  /* To pass vect_analyze_loop.  */
            goto vectorize_epilogue;
          }
      }

  vect_location = UNKNOWN_LOCATION;

  statistics_counter_event (cfun, "Vectorized loops", num_vectorized_loops);
  if (dump_enabled_p ()
      || (num_vectorized_loops > 0 && dump_enabled_p ()))
    dump_printf_loc (MSG_NOTE, vect_location,
                     "vectorized %u loops in function.\n",
                     num_vectorized_loops);

  /*  ----------- Finalize. -----------  */

  if (any_ifcvt_loops)
    for (i = 1; i < vect_loops_num; i++)
      {
        loop = get_loop (cfun, i);
        if (loop && loop->dont_vectorize)
          {
            gimple *g = vect_loop_vectorized_call (loop);
            if (g)
              {
                fold_loop_vectorized_call (g, boolean_false_node);
                ret |= TODO_cleanup_cfg;
              }
          }
      }

  for (i = 1; i < vect_loops_num; i++)
    {
      loop_vec_info loop_vinfo;
      bool has_mask_store;

      loop = get_loop (cfun, i);
      if (!loop)
        continue;
      loop_vinfo = (loop_vec_info) loop->aux;
      has_mask_store = false;
      if (loop_vinfo)
        has_mask_store = LOOP_VINFO_HAS_MASK_STORE (loop_vinfo);
      destroy_loop_vec_info (loop_vinfo, true);
      if (has_mask_store)
        optimize_mask_stores (loop);
      loop->aux = NULL;
    }

  free_stmt_vec_info_vec ();

  /* Fold IFN_GOMP_SIMD_{VF,LANE,LAST_LANE,ORDERED_{START,END}} builtins.  */
  if (cfun->has_simduid_loops)
    adjust_simduid_builtins (simduid_to_vf_htab);

  /* Shrink any "omp array simd" temporary arrays to the
     actual vectorization factors.  */
  if (simd_array_to_simduid_htab)
    shrink_simd_arrays (simd_array_to_simduid_htab, simduid_to_vf_htab);
  delete simduid_to_vf_htab;
  cfun->has_simduid_loops = false;

  if (num_vectorized_loops > 0)
    {
      /* If we vectorized any loop only virtual SSA form needs to be updated.
         ???  Also while we try hard to update loop-closed SSA form we fail
         to properly do this in some corner-cases (see PR56286).  */
      rewrite_into_loop_closed_ssa (NULL, TODO_update_ssa_only_virtuals);
      return TODO_cleanup_cfg;
    }

  return ret;
}


/* Entry point to the simduid cleanup pass.  */

namespace {

const pass_data pass_data_simduid_cleanup =
{
  GIMPLE_PASS, /* type */
  "simduid", /* name */
  OPTGROUP_NONE, /* optinfo_flags */
  TV_NONE, /* tv_id */
  ( PROP_ssa | PROP_cfg ), /* properties_required */
  0, /* properties_provided */
  0, /* properties_destroyed */
  0, /* todo_flags_start */
  0, /* todo_flags_finish */
};

class pass_simduid_cleanup : public gimple_opt_pass
{
public:
  pass_simduid_cleanup (gcc::context *ctxt)
    : gimple_opt_pass (pass_data_simduid_cleanup, ctxt)
  {}

  /* opt_pass methods: */
  opt_pass * clone () { return new pass_simduid_cleanup (m_ctxt); }
  virtual bool gate (function *fun) { return fun->has_simduid_loops; }
  virtual unsigned int execute (function *);

}; // class pass_simduid_cleanup

unsigned int
pass_simduid_cleanup::execute (function *fun)
{
  hash_table<simd_array_to_simduid> *simd_array_to_simduid_htab = NULL;

  note_simd_array_uses (&simd_array_to_simduid_htab);

  /* Fold IFN_GOMP_SIMD_{VF,LANE,LAST_LANE,ORDERED_{START,END}} builtins.  */
  adjust_simduid_builtins (NULL);

  /* Shrink any "omp array simd" temporary arrays to the
     actual vectorization factors.  */
  if (simd_array_to_simduid_htab)
    shrink_simd_arrays (simd_array_to_simduid_htab, NULL);
  fun->has_simduid_loops = false;
  return 0;
}

}  // anon namespace

gimple_opt_pass *
make_pass_simduid_cleanup (gcc::context *ctxt)
{
  return new pass_simduid_cleanup (ctxt);
}


/*  Entry point to basic block SLP phase.  */

namespace {

const pass_data pass_data_slp_vectorize =
{
  GIMPLE_PASS, /* type */
  "slp", /* name */
  OPTGROUP_LOOP | OPTGROUP_VEC, /* optinfo_flags */
  TV_TREE_SLP_VECTORIZATION, /* tv_id */
  ( PROP_ssa | PROP_cfg ), /* properties_required */
  0, /* properties_provided */
  0, /* properties_destroyed */
  0, /* todo_flags_start */
  TODO_update_ssa, /* todo_flags_finish */
};

class pass_slp_vectorize : public gimple_opt_pass
{
public:
  pass_slp_vectorize (gcc::context *ctxt)
    : gimple_opt_pass (pass_data_slp_vectorize, ctxt)
  {}

  /* opt_pass methods: */
  opt_pass * clone () { return new pass_slp_vectorize (m_ctxt); }
  virtual bool gate (function *) { return flag_tree_slp_vectorize != 0; }
  virtual unsigned int execute (function *);

}; // class pass_slp_vectorize

unsigned int
pass_slp_vectorize::execute (function *fun)
{
  basic_block bb;

  bool in_loop_pipeline = scev_initialized_p ();
  if (!in_loop_pipeline)
    {
      loop_optimizer_init (LOOPS_NORMAL);
      scev_initialize ();
    }

  /* Mark all stmts as not belonging to the current region and unvisited.  */
  FOR_EACH_BB_FN (bb, fun)
    {
      for (gimple_stmt_iterator gsi = gsi_start_bb (bb); !gsi_end_p (gsi);
           gsi_next (&gsi))
        {
          gimple *stmt = gsi_stmt (gsi);
          gimple_set_uid (stmt, -1);
          gimple_set_visited (stmt, false);
        }
    }

  init_stmt_vec_info_vec ();

  FOR_EACH_BB_FN (bb, fun)
    {
      if (vect_slp_bb (bb))
        dump_printf_loc (MSG_OPTIMIZED_LOCATIONS, vect_location,
                         "basic block vectorized\n");
    }

  free_stmt_vec_info_vec ();

  if (!in_loop_pipeline)
    {
      scev_finalize ();
      loop_optimizer_finalize ();
    }

  return 0;
}

} // anon namespace

gimple_opt_pass *
make_pass_slp_vectorize (gcc::context *ctxt)
{
  return new pass_slp_vectorize (ctxt);
}


/* Increase alignment of global arrays to improve vectorization potential.
   TODO:
   - Consider also structs that have an array field.
   - Use ipa analysis to prune arrays that can't be vectorized?
     This should involve global alignment analysis and in the future also
     array padding.  */

static unsigned get_vec_alignment_for_type (tree);
static hash_map<tree, unsigned> *type_align_map;

/* Return alignment of array's vector type corresponding to scalar type.
   0 if no vector type exists.  */
static unsigned
get_vec_alignment_for_array_type (tree type) 
{
  gcc_assert (TREE_CODE (type) == ARRAY_TYPE);

  tree vectype = get_vectype_for_scalar_type (strip_array_types (type));
  if (!vectype
      || !TYPE_SIZE (type)
      || TREE_CODE (TYPE_SIZE (type)) != INTEGER_CST
      || tree_int_cst_lt (TYPE_SIZE (type), TYPE_SIZE (vectype)))
    return 0;

  return TYPE_ALIGN (vectype);
}

/* Return alignment of field having maximum alignment of vector type
   corresponding to it's scalar type. For now, we only consider fields whose
   offset is a multiple of it's vector alignment.
   0 if no suitable field is found.  */
static unsigned
get_vec_alignment_for_record_type (tree type) 
{
  gcc_assert (TREE_CODE (type) == RECORD_TYPE);

  unsigned max_align = 0, alignment;
  HOST_WIDE_INT offset;
  tree offset_tree;

  if (TYPE_PACKED (type))
    return 0;

  unsigned *slot = type_align_map->get (type);
  if (slot)
    return *slot;

  for (tree field = first_field (type);
       field != NULL_TREE;
       field = DECL_CHAIN (field))
    {
      /* Skip if not FIELD_DECL or if alignment is set by user.  */ 
      if (TREE_CODE (field) != FIELD_DECL
          || DECL_USER_ALIGN (field)
          || DECL_ARTIFICIAL (field))
        continue;

      /* We don't need to process the type further if offset is variable,
         since the offsets of remaining members will also be variable.  */
      if (TREE_CODE (DECL_FIELD_OFFSET (field)) != INTEGER_CST
          || TREE_CODE (DECL_FIELD_BIT_OFFSET (field)) != INTEGER_CST)
        break;

      /* Similarly stop processing the type if offset_tree
         does not fit in unsigned HOST_WIDE_INT.  */
      offset_tree = bit_position (field);
      if (!tree_fits_uhwi_p (offset_tree))
        break;

      offset = tree_to_uhwi (offset_tree); 
      alignment = get_vec_alignment_for_type (TREE_TYPE (field));

      /* Get maximum alignment of vectorized field/array among those members
         whose offset is multiple of the vector alignment.  */ 
      if (alignment
          && (offset % alignment == 0)
          && (alignment > max_align))
        max_align = alignment;
    }

  type_align_map->put (type, max_align);
  return max_align;
}

/* Return alignment of vector type corresponding to decl's scalar type
   or 0 if it doesn't exist or the vector alignment is lesser than
   decl's alignment.  */
static unsigned
get_vec_alignment_for_type (tree type)
{
  if (type == NULL_TREE)
    return 0;

  gcc_assert (TYPE_P (type));

  static unsigned alignment = 0;
  switch (TREE_CODE (type))
    {
      case ARRAY_TYPE:
        alignment = get_vec_alignment_for_array_type (type);
        break;
      case RECORD_TYPE:
        alignment = get_vec_alignment_for_record_type (type);
        break;
      default:
        alignment = 0;
        break;
    }

  return (alignment > TYPE_ALIGN (type)) ? alignment : 0;
}

/* Entry point to increase_alignment pass.  */
static unsigned int
increase_alignment (void)
{
  varpool_node *vnode;

  vect_location = UNKNOWN_LOCATION;
  type_align_map = new hash_map<tree, unsigned>;

  /* Increase the alignment of all global arrays for vectorization.  */
  FOR_EACH_DEFINED_VARIABLE (vnode)
    {
      tree decl = vnode->decl;
      unsigned int alignment;

      if ((decl_in_symtab_p (decl)
          && !symtab_node::get (decl)->can_increase_alignment_p ())
          || DECL_USER_ALIGN (decl) || DECL_ARTIFICIAL (decl))
        continue;

      alignment = get_vec_alignment_for_type (TREE_TYPE (decl));
      if (alignment && vect_can_force_dr_alignment_p (decl, alignment))
        {
          vnode->increase_alignment (alignment);
          dump_printf (MSG_NOTE, "Increasing alignment of decl: ");
          dump_generic_expr (MSG_NOTE, TDF_SLIM, decl);
          dump_printf (MSG_NOTE, "\n");
        }
    }

  delete type_align_map;
  return 0;
}


namespace {

const pass_data pass_data_ipa_increase_alignment =
{
  SIMPLE_IPA_PASS, /* type */
  "increase_alignment", /* name */
  OPTGROUP_LOOP | OPTGROUP_VEC, /* optinfo_flags */
  TV_IPA_OPT, /* tv_id */
  0, /* properties_required */
  0, /* properties_provided */
  0, /* properties_destroyed */
  0, /* todo_flags_start */
  0, /* todo_flags_finish */
};

class pass_ipa_increase_alignment : public simple_ipa_opt_pass
{
public:
  pass_ipa_increase_alignment (gcc::context *ctxt)
    : simple_ipa_opt_pass (pass_data_ipa_increase_alignment, ctxt)
  {}

  /* opt_pass methods: */
  virtual bool gate (function *)
    {
      return flag_section_anchors && flag_tree_loop_vectorize;
    }

  virtual unsigned int execute (function *) { return increase_alignment (); }

}; // class pass_ipa_increase_alignment

} // anon namespace

simple_ipa_opt_pass *
make_pass_ipa_increase_alignment (gcc::context *ctxt)
{
  return new pass_ipa_increase_alignment (ctxt);
}